<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            list-style: none;
        }
        div {
            width: 80px;
            height: 22px;
            background-color: gray;
            cursor: pointer;
        }
        ul li {
            float: left;
            color: gold;
        }
    </style>
</head>
<body>
    <div>
        <ul>
            <li>☆</li>
            <li>☆</li>
            <li>☆</li>
            <li>☆</li>
            <li>☆</li>
        </ul>
    </div>
    <script src="./jquery-1.12.4.min.js"></script>
    <script>
        var $lis = $("div ul li")
        $lis.each(function(){
            $(this).on("mouseenter",function(){
                $(this).prevAll().text("★")
                $(this).text("★").nextAll().text("☆")
            })
        })
        $lis.each(function() {
            $(this).on("mouseleave",function(){
                $(this).text("☆").prevAll().text("☆")
            })
        })
    </script>
</body>
</html>